text: Utilising the tidal prism for velocity calculations in the neck of a tidal inlet
  If a tidal basin is relatively short (i.e., its length is minor compared to the tidal waves length), its assumed that the basins water level remains even, merely rising and falling with the tide. Under this assumption, the basins storage (tidal prism) equals its surface area times the tidal range.
  The formula for basin storage then simplifies to:
  : , in which:
  :*  represents the tidal prism (m),
  :*  signifies the basin area (m),
  :*  denotes the tidal range at the basin's entrance (m).
  This methodology facilitates a reliable estimation of current velocities within the tidal inlet, essential for its eventual closure. Termed the storage area approach, this technique provides a straightforward means to gauge local hydraulic conditions essential for barrier construction.
  Within this approach, estuary water movement is modelled without either friction and inertia effects, leading to:
  in which  is the flow rate in the inlet,  is the basin storage area, and  is the water level's rate of change.
  The depicted basin storage system assumes:
  * A river discharge , with inflow considered positive,
  * A flow through the closure , governed by the energy height difference upstream  and water level at the gap , along with the gap's drainage characteristics.
  For an imperfect weir:
  And for a perfect weir:
  Symbol meanings are as follows:
  Combining these yields the basin storage equation, facilitating velocity graphs within the closure gap. An example graph for a tidal amplitude of 2.5 m (therefore a total range of 5 metres) shows velocities as functions of the tidal storage area (B) to closure gap width (W) ratio and sill depth (d'). Red indicates vertical closures, orange horizontal, and green a combination, highlighting the speed differences between closure types.